I’m planning to have another attempt at cutting aluminium. My experience and what I’ve read on this forum leads me to think that it’s possible as long as it’s done within certain parameters, i.e. fast feed speed, slow rpm and small DOC. The final thing is to make sure the chips can clear so this needs a cut wider than the bit.
I’ve considered a contour cut using stepover pass (using a 3mm two flute flat end mill), i.e.
This is OK but I’m sure there is a way to configure an adaptive clearing toolpath to do the job. If I configure adaptive clearing on the circle then it wants to clear the whole area rather than just a wide path around the inside of the circle I want to cut out.
Is there a way to use Adaptive clearing to behave like a Contour path?
The biggest issue is dealing with lack of rigidity.
Get the machine is rigid as possible, especially Z-axis is very important for the success rate.
You can go shallow DOC as you mention, trade-off is machining time.
No need either to carve the whole inside, a cutout is enough. (as you say)
If you use a 3mm bit and say 9mm wide channel for cutout you can use the combination of 2D Adaptive for roughing and a plain Contour for finishing.
With 2D Adaptive you can go deeper per pass (try 1,5mm or 3mm DoC) but keep WoC (Width of cut) shallow. The bit make a helical plunge to depth then start doing slices.
The benefit of this is primarely:
- You use a larger part of the cutter edge = less wear
- The 9mm wide channel / tool path make chip clearing easy
Also see this - https://www.youtube.com/watch?v=8D8livGvnUY
Don’t have time to explain now, but if you share your Fusion project I can show you what I’d do. Later.
Yes, exactly what I was thinking about Neil 
Thanks both. I think I’m on it now. Extrude the circle then draw a circle within it to bound the adaptive clearing.